A wide variety of electronic devices employ a video display, such as a Liquid Crystal Display (LCD) or Organic Light-Emitting Diodes (OLED) display, and one or more input devices, which can be mechanically actuated (e.g., switches, buttons, keys, dials, joysticks, joy pads) or electrically activated (e.g., touch pads or touch screens). The display is typically framed by a bezel and configured to present visual content such as text and graphics, and the input devices are typically configured to perform operations such as issuing commands, making selections, or moving a cursor or selector within a display area of the display. Each of these well-known devices imposes design restrictions such as size and shape limitations, costs, functionality, complexity etc., that must be taken into account when designing the hand-held electronic device. In most cases, the display is an integral part of the user experience with the product by providing dynamic display of information such as status or feedback information or other visual content to the user.
This fact makes touch-sensitive interfaces, wherein the user selects or inputs information by touching a portion of the display, particularly compelling. Accordingly, such touch-sensitive display devices are commonly found hand-held electronic devices, including, for example, telephone receivers, PDAs, media players, remote controls, cameras, global positioning systems, portable computers, and kiosk displays.
A typical touch sensitive display system 1 of the prior art is shown in FIG. 1. In the example shown in FIGS. 1 and 2, the touch sensitive display system 1 comprises a housing which forms a bezel 2. Bezel 2 is configured with an opening 4 in which a display 6 is mounted, such that bezel 2 allows the user to view substantially all of an active viewing area of display 6.
FIG. 2 shows one example of a prior art display 6 of a type that is commonly used in the touch sensitive display system 2 shown in FIG. 1. As shown in FIG. 2, display 6 typically has many functional elements, including active viewing area 20, which is comprised of an array of light-emitting or light-modulating elements, a display support 22, and electrical connections for the column drivers 24 and electrical connections for the row drivers 26.
Referring again to FIG. 1, bezel 2 typically precludes the user from seeing the display housing 22 and electrical connections for the column drivers 24 and the row drivers 26. To perform this function, bezel 2 must be wide enough on at least two sides to cover the extent of the electrical connections, however, for aesthetic reasons, bezel 2 is typically equally wide along the two horizontal sides of the device and at least as wide along the vertical edges as the horizontal edges.
In devices employing touch screen technology, a substantially transparent cover plate 8 is typically provided to protect the display from mechanical stress and a touch-sensitive overlay 10 is positioned on cover plate 8. Touch-sensitive overlay 10 is typically not truly transparent, but instead is somewhat semi-transparent, and has the effect of absorbing some of the light generated by display 6, thereby reducing the effective luminance of images presented by display 6.
Further, touch-sensitive overlay 10, is typically made of materials that diffuse light that passes through it. This has the effect of reducing the perceived sharpness of an image presented by display 8 and, perhaps more importantly, diffusely reflects any light that impinges on this layer from the ambient environment. This diffuse reflection of ambient light detracts from the overall user experience and the value of the product as may be evidenced by the recent increase in sales of laptop personal computers that incorporate displays having highly specular front surfaces and the accompanying decrease in the sales of laptop computers having displays with highly diffused front surfaces.
One known way to remove the touch-sensitive overlay 10 from the display design is to include light-sensitive elements in the surface of display 6. For example, U.S. Pat. No. 7,184,009 to Bergquist, issued Feb. 27, 2007, entitled “Display circuit with optical sensor,” and U.S. Pat. No. 6,717,560 to Cok et al., issued Apr. 6, 2004, entitled “Self-illuminating imaging device,” provide discussions of displays having embedded light-sensitive elements that may be used for light sensing. Unfortunately, such display designs require that the circuitry for driving the display, the circuitry for sensing, and often the light-emissive elements of the display to share area on the display surface. Therefore, incorporating such elements into the display to enable a touch screen without providing a touch-sensitive overlay often requires the use of smaller light-emitting elements which often degrades the lifetime of displays such as OLED displays or reduces the power efficiency in displays employing light modulators, such as liquid crystal displays.
It will be appreciated that the use of any touch-screen technology requires the user to make physical contact with active viewing area 20 of display 6 and/or cover plate 8, or touch-sensitive overlay 10. Such contact can have undesirable consequences. For example, the act of touching the display can deposit oil, dirt and/or other contamination on the surface of the display 6, cover plate 8, and/or touch sensitive overlay 10 which can interfere with the optical performance of the display 6. Avoidance of surface contamination may be of particular concern when one of the primary purposes of the display 6 is to present images or video that are to be viewed for aesthetic or entertainment purposes. Further, any display which has an active viewing area 20 with a touch-sensitive surface must be robust to such touching to enable both reliable sensing of the contact and reliable operation of the display 6 and/or touch sensitive overly 10 over the useful life of the electronic device into which they are incorporated. This typically involves increasing the physical robustness requirements of the display 6, cover plate 8 and/or touch-sensitive overlay. These requirements can cause a substantial increase in the thickness, weight, complexity or the total system cost of the display system.
In a touch screen system, the above described sensing functions comprise only one portion of the overall graphical user interface provided using the touch-screen display. This is depicted on a touch-sensitive user interface contains several elements that are important to its operation. One such graphical user interface is shown in FIG. 3. Note that this graphical user interface typically contains informational messages 30, and typically two or more options 32a, 32b. Further, the graphical user interface typically consists of a user selection area 34a, 34b, which indicates the location of the physical area that must be touched to select an option.
Among the advantages of touch-sensitive interfaces, is that the options can be updated as they change or become relevant to the user. This is a significant improvement over interfaces having physical buttons that are inextricably tied to a single function. Instead, a single touch sensitive area can serve the function of 10s, 100s, or even 1000s of buttons containing fixed physical labels. Without the ability to adjust the user interface in this way, it would be basically impossible to provide the user with a large number of features or to enable multi-function devices.
It is also known, however, to employ fixed physical buttons in conjunction with a displayed image as described by U.S. Pat. No. 6,680,749 to Anderson et al., issued Jan. 20, 2004, entitled “Method and system for integrating an application user interface with a digital camera user interface,” allowing the user to select among a few fixed options. Unfortunately, in these interfaces, the number of buttons is fixed and novice users sometimes have difficulty associating a physical button with an adjacent region on a screen since there is not a direct physical association or visual connection between the touch sensitive button and the option on the display. Further, this embodiment, requires a region of the display within the bezel to be allocated for depicting user interface options to the user and precludes the use of this portion of the display for displaying information, such as images.
King et al., in U.S. Application Publication No. 2006/0238517, entitled “Electronic Device Having Display and Surrounding Touch Sensitive Bezel for User Interface and Control”, has discussed another option in which a display is positioned on the electronic device and having a perimeter or bezel; at least one touch sensitive surface is positioned on the electronic device adjacent at least a portion of the perimeter of the display; and processing circuitry is connected to the display and the touch sensitive surface. Within this device, the processing circuitry designates at least one area of the at least one touch sensitive surface for at least one control; generates at least one visual guide for the at least one control; and presents the at least one visual guide for display at a location on the display adjacent the at least one area designated for the at least one control. Note that in this embodiment, the visual guide is located on the display inside the bezel but indicates a touch-sensitive surface that is located on the bezel. While this solution overcomes many of the stated problems with existing touch sensitive and button interfaces, it requires that a portion of the display area inside of the bezel be allocated for user interface options and again requires the user to associate an area outside the display with an option that is on the display.
Each of these solutions has additional problems within certain applications. For example, some products, such as digital picture frames, serve a primary function of providing aesthetically pleasing decoration, including an image and a decorative frame. Therefore, it is undesirable to place physical buttons onto the frame or digital touch overlays over the image. However, it is often important for the user to interact with such products to change attributes such as which images are displayed, how they are displayed, or to load new images into the memory of the digital picture frame. Therefore, it is necessary to provide an interface that is invisible to the user when the product is providing its primary function of providing an aesthetically pleasing decoration while also providing an intuitive user interface that may be accessed when the frame is hung on the wall. The prior art does not provide a solution for such a problem.
Therefore, there is a need for an improved user interface that allows the dynamic display and touch-sensitive selection of context-sensitive user controls without applying a touch-sensitive overlay to the portion of the display area inside the opening of the bezel but allowing the direct association of these context-sensitive user controls with touch sensitive areas. Further, such an interface should not be visible during the products primary mode of operation and yet be intuitive to use.